SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c2e3f28d0df86f5cb9200bb69e163fa6d08f0896427ee56423893cfb9aa78cb' 
  AND token = 'jdq09yPWJltLbtNajypppurQtvv0fPGZw5zVKMadwZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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