SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '768ed0330bfb8b539755dfb09e356f8b2c7ccd0a6d533b51f4744e79eded8996' 
  AND token = 'SIIUofVSMpoJyEaoQEBKqJ9EcA94xEeTCqDHPrnREKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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