SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17ca656e8b40aa64eec8de0150d363b92edde353053289d5d489e53a3d4aeedb' 
  AND token = 'sQziGAFyGV8f1HCt2b7m6Ncy5aniNW0TvsafLgGsy4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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