SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a544b43bf75ab1cdd0b6e45636646f29e81374171c4060a393a16abc9f6649e' 
  AND token = 'vBB40Sj2yJznqtbVOG18yYl0Vs4sNcUnPjrZvuWXkvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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