SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45a69ec2f4ae874dd4da5e2a5b933faf6a73bdaf15d7b691abbea86bbf083686' 
  AND token = '48RQYsK3Bd3ndWhB0a0HoECHkpgXD85ulXXC/CQhvMY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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