SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12220dc09d1abfc5df8562158d83f2f6b8ba77054417d93e5d35719ce7615d25' 
  AND token = '9Ten7ZGSmsZP5RygUzWdPt+CGsDuK/Ir+XI72WLHnjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}