SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27208ba8b2d8fea101d5be5a0bb36e3a233edb7f4a873ad140c10985650421b9' 
  AND token = '/Bp/riSnmgzJVwA3AUIK3GdfDwpmvPNN/COEeYYx/9M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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