SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0331e02c40e5ea8df192510d19cb35b9ceea8f177eeeeb4797854946b38f1200' 
  AND token = '05RsuBTuv5F2DWciYLiftw5KpmdOLddlNEsGiWtcoKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}