SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '832e899ee69163c9a10d7c76674ba887392bfb968d6e559c2cebe75f0274782c' 
  AND token = 'ZnJlSSS7JPRb+ST6/ui1e5Hpbsk8BRFAdhZXINzdNLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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