SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53196115e15c4bb73361d9fe37dd1bb6c76c282d5b58698bbceef6b89d00e4fc' 
  AND token = 'lc3ZDOQJgw6MDqlaekhphT0ZWeajZmE950VGuV6ivZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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