SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ef7490d6af0965c147ef4edec67aab89bb21b527cf33daa85eb2a69274c2656' 
  AND token = 'rIjlWCOFbFqm+pNcqeJ3z/z7WUoalfHCszTCl/+a7dk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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