SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bba9ccdcd62f0589af3fa6bf1b780d3a12ad5a5d42ccfc4b9671df49238d12b' 
  AND token = 'FUDcKIJ1rZf3zTQZ801taY4upUA8BUflsSL61ttTntY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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