SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0acc4407b34d6dfb768ca73d0bd4ef1519a75f92742b1c656d5428e376de8af9' 
  AND token = 'RYS87b2VbLgTW9ewxGqNXC6LcWZj5YCtqRo13JxUBF4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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