SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eca7e1509fe3047dc47886490c668fc1bf32294ecfd57d1f0a0d0b10b9e2fc39' 
  AND token = 'IZkhQDkBtpVhDxV/sHn5k+/KFxy7k/PIrXyegb40Y+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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