SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f14aaa77c8ad1e825b901febe93a732192c864bec4c8ca2543fdbf0b2466406' 
  AND token = 'D0vB3vUpky6cNLWTX8uBAUM0tOQwR3CpWmsdryMZYrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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