SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '823a14f457d2ad7b47963d652dbd048f2da16ad54b5c866e2fd0e1b291bd482b' 
  AND token = 'Q8Yz3fuJeI/uvunXXR94eUw2JDKOzL+vXodsb7U3VI4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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