SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e615e5764afc319a1558946569799d0eff9b8fc00673e09ec2066a1a87e8d322' 
  AND token = 'HkifO6QDPBErIQK/QeSm1X4Q6jD7G8F2E656ptTZ4J8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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