SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b44cb28faae2f6d503902d82035e3b2e281cf0344ac2fabe45a91b696c03558a' 
  AND token = 'Ukor1Neyj+X+g9MhRVx/D/CzseGFuUfwl2tcZHFUYXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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