SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bc604e188183c34d8071eba4375953644fbbd68db8b87493874c8ecb46fc14d' 
  AND token = 'GxgksDY5tDwPi8PZ0AU2Em8YPxQp4MiNyDe6QGY3tAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}