SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fd0a621d9981a7027d0bbe677a6db0f162654eeff44092d779416771d76badd' 
  AND token = 'KePqbAb+sy8QyDWcyhzNTMzU0Ea8MFxMwnYT4AYoaBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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