SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd34061a44baf35db0f176587320d53b9e2f187bc32330230aa40c04c68483a2' 
  AND token = 'xYAiqT+WKSRpoI1wZS4LhvjdqJoduYT8jQ4GoUVwKlc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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