SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c42d92f4bfd2ad29510911102ee5f7284d7b6642695ecbcc8675ed8f9a467e29' 
  AND token = 'EAkwM9Dzl58WrAVItD6vPSOsnh6POkskJ+DREGBRJzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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