SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b3da9b6e6121c262d962e68b68e80588c6061f7a64184148683e361b6966019' 
  AND token = '9mm9KbC/pX0kMbaT5E6cjkmkBtuygbQLNtimwEggVPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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