SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29d456997234c331476839351883a33601bcefe78a6e7af32d751021794b6eef' 
  AND token = 'NzvBED4ZiQ5bKu9SVBdoYtg5xSV8dMu6OWx9fJ5G/sw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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