SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '228fde5eb594094c227ce694043714425c5519219393c9b810055fa69c015eff' 
  AND token = 'uTxB39gDg3tp5UEP6AsuJc3aR/NpkGN3wI7kPIGhAQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}