SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23b080fa13483df44142b34174a6c1081bfe59049f97ff5aaa6a4650c23f7870' 
  AND token = '9rbo5guiuFUHmt+bdVrgxiDxbZvpr2KkJwWgpnk24qg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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