SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecc8fa22dd2c941625e5672651bbc27630a8ade8dab3858911a8a97f91aa841c' 
  AND token = 'k9IIExPFkgt7BOrmj2p+NvIh+GZvl1X95uIm7FB/7aE=' 
  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"
    }
  }
}