SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82d86bbc7104bc9e306238493cb33f6b21171e610c3d629195405dba89adbbd6' 
  AND token = '0BngE6GSxgwV+qOoFQa5vuwrzZI44Qfpm9hkoK1meFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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