SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93831905326b79c5cbc39bdb21d6e76f2eadbc79c6c9f316a3bfed836e7b62cd' 
  AND token = 'yDEsyP/Pa3ZfSKYiFtU+EnZpj7yht5vRhLrqlSLhx4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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