SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3ac4c57c42f50e2ff223418d361588d2e041c9da0560e570663b33334d9aee9' 
  AND token = 'qD8Cgaiaxtca/MdvqusxcF7U7xEDDIjZaP3UdNqTgck=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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