SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdaf455e634471a37b8ece1d82817df9a4dd6d0548bb5b6737c65fa59df3130e' 
  AND token = 'HYtP40TmusADNQhZj3nDKUnBVnDn7/62TYh90bv+pGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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