SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b1f602f9131de5eee1ffb43ea8a23f2ee647ecfb25c8daaacbabc491f6a356f' 
  AND token = 'IHRAYkVIrzZd0g96UtTaj6KJ2lpwGh7GDPGF5z4YSmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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