SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ff614abef050cd30afe7f4b239271a46c0044c564f3c5c4b4727cd96bcd2dd1' 
  AND token = 'L9lPhArqS+pzJS/xVwTSylLsxumQ7YYDc8u1S+vDyVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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