SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfcab8e11f46593e6194a9273a273b7a43b0dbc273aa2283bda182776ad5492b' 
  AND token = 'I4+6KZWNLH7CM6o8WZw4LnmDukqtnCUttmNHhhSN+Zg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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