SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a8b02979dea2c5026db153cfb0deee716bf448a454fc4d63b43095094f35ed7' 
  AND token = 'k6oVuMr7HSfXV5QGE9Sp9HqXsKhna6o+pzJKIZcNQgI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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