SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08b17788a3572e5c72fb0f857998673833f2a7c81817015aabe79a00d393bf02' 
  AND token = '6B9yTemkjdHpmIGvS84XHsqlM+N+KXY4FGHocK3tEUU=' 
  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"
    }
  }
}