SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9410728f8862cba8c96822561bae4cec0c73cf60bdcf799040f1261e7fb50272' 
  AND token = 'dEvt4qfzMRMKjDe3OEMct3vpneFbDaeux1fmxtVvY84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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