SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a7867ff239f4398bdccacb0ed3820c4592d5ffa6d3b1816190a1eaf4c09d133' 
  AND token = 'HsEVWyzUKnxljkNZaSqudEBMmOVfJXEkDx92UBHQMqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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