SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf1526f970ec84bc40b7152c916bc82b44970eb8cbe5a6f44a9ce10590d044a3' 
  AND token = 'fdSxwobOKJhH6yNqyMGB4BCtGu5Ybmb+1PoaaHF/OGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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