SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3e692d5a01508793f1f2bb82b8d7c0ae28119a36557027a4bbc5336c2634f1e' 
  AND token = 'fNuLIm123pMEfa2dHx4QGMnaUk6iLxdYtkjj7nKRX58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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