SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38d52cbc7600b32e700bf8787b90833cac1b4a121084c2de5072a7e8a2d53bac' 
  AND token = 'lHndZJx+V1Iymq4YmxbbmmzYRBIRFU5swSSuqJw/6/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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