SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a6a64733d595fe5768575031cf11408ea0a455f8bc12581af7e574843680ae3' 
  AND token = 'aK5FF5l0GzaPZJ1M8yxnXAtd1U1z4oHh9Uwn73GqjfE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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