SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3aa4e680258d9a8691e0ba2ab8753d8e80344bf5500165079982fdea68c16c71' 
  AND token = 'fs7hotb3azOMhqwkrIa7U6Y44gpqj2vJXGpymi0e/Sk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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