SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59ec33943a709bcfe21f0edc2bba0d8e4214fb52fbff80cf6b0cddcdc4fa8cb8' 
  AND token = 'GIp/Vfjp+NRiZhT6lMTzjKyqcd8wa//RFcBCDKYRPmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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