SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fd35b5ab031883d1b732ecc114e0f89d4dc3e345d6bb72945b3e057904bf206' 
  AND token = 'gfuw1PDELAHHCJ/x1mgVqXgCs9PUv5lGonQTPpP4zrE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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