SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc2d9f5a1667809b72f4981a0471f100b6e529e1d98a735df4c3a1aac8baa239' 
  AND token = 'NCKwKAme2bY0YXCGZMI2qqhrLNq5O70fRY9zhRDGwQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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