SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25f40787a434ea72aa8db17eda6ee68635ba28f95306631a091e96995c58528d' 
  AND token = 'KldXsVX19hQAncHcsvX3Wk6iw2PRd1H1IreUbXuwYz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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