SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abac30d237007320cbff4340d5ec24bed41f375d5766a3c1705db58cee794210' 
  AND token = 'qjggem40NItoad+PyXUhnPOxs6M1UEQoiwMC8EgPqNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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