SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c0a9cc2f1a79c7ad682725b43c7c7eb18345dbb9b42b61fba1f3ac1dae89745' 
  AND token = '4218V25sFRf8VWPVKQMZzzs/ZozIfOOQwVgVGIFvrD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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