SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef4c0629628b357998efc5f6c03e7de79b1bf35e113721409d322bec567f8d85' 
  AND token = 'HRFyKnO8zZ3Ioli50FSvymuwixnx0g5sRKmHhukJ9E0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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