SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46399c9759c236e45fff3f2ee6d8916599683bc14c1229a5a075abb09ed74547' 
  AND token = 'Kbwt183io49wDBHQJOIv/i6emVLuKqCAGB9EQQ3SAn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}