SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e037e0b563fefea4f098d99bb10a82c9c44e12da0b90a7983e9d03f838ff8a36' 
  AND token = 'dk27+0AJDZIwIUP0GVSTNTEDkTfCk0TTFn4Zz8G4baM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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