SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '026f55400cb4c8a0399539f2ecefda796287d91ca094931d2123aaac96dbbd7c' 
  AND token = 'sfzLutS39xvEMGIsSiZezoMwyCbmc/zTBhx2qsHCwIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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