SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '305e9722f9a5ff7fe7cefd47a281c8319e0b83ca70a468125b3c921704bcc299' 
  AND token = 'q26ItKc4OHSqlSolLTvp6wu75VSK2gMOJOfnvL8XReo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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