SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7a3b17f949f66cb0cb9bd4642512e91e5b89426ebfa92c75e96e0ad15513bec' 
  AND token = 'RAyi2Lp68e8whMZ6wRy8KEE6xCn3UF3FLy4AJekl6ko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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