SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '222e300be3c74e9fd795dc73f1caa43f5101fc22436c5497f48fe08049a9d875' 
  AND token = 'KZ3+Hx1Teby0UYhn0jZ7/EJh1BpGEuYfwqVLqjMGD30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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