SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64c7d6e1d5a3333b54452b806b2fce252e1727124628329c7479a2f6a75d15a4' 
  AND token = 'Gp0M8rhZKyxWQgvPc+QqafdytZCuCVTF8r/vOWD9sr8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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