SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b4171247b9fbe5fde1c9b909a97c752b5e07cb28711399374541231604a6114' 
  AND token = 'yFwnek11azlXbovzluAOfFwjSu/+lwgddlORJ1PCFd8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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