SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4929234a63445b8f499a1fced36515891a039b32df51da01370bb0df86c1a82' 
  AND token = 'VvvQ+7TeENZWaRtse0BEPuPUlqLr2o+JD10w95j8A3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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