SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3b63bbd73a429c00601f81d54e1b7d41681b28c3f667a6c674968e8834e0912' 
  AND token = 'sl+fFcJYYLq2cUdf3C/KHr7TSQihgmzJ3TzeegjsEQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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