SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '126ba96051cafba36d532879485df226dda3a92c9b74075921d3ac62735aab37' 
  AND token = 'YsWZht3BLzXmkmoGaq+j4m6gD1vBpDC1+qS1Lvx7Fhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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