SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8a7c72083bb85cd2ef2c7c92afde66466dc295e74f725e49482d35e601243dd' 
  AND token = '1j5o2zd/dyiZdY2YgJkv12IODfKMLsidOdCz0q1hdGQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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