SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2abbffbffc29498787dbf49b422526efe3e21f67511c5e995c6486edac3c51aa' 
  AND token = 'rtK75iGybEhDuAGiuW+LuPUEpWQzk5e7fvj2wdTVsfc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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