SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '333889dfd3f96835d294d813c5e76bf9bdf96206ac4d87fa22194ef449f3e037' 
  AND token = 'qqdb3eW4TPeYy8nhXuuo3fy9aAsQbqSoWvp5vZTwftI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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