SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a2f6009ddb29d5e2814137667c33a0244fa570b8d6554ca1f8e6af452c02f30' 
  AND token = 'nqKrEVtqGK9wgb36fjgnyUoLcJ2PTq16JTImygvindk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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