SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2884d72a2d47fdeb029d95d2401b7c5c1493b65fd99b09bcc406f7ca71b8f168' 
  AND token = 'gC+sut2Ph+KfzqBPv1FBCyQsgQ/ljF8ymn0HHDhRvSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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