SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96a774c9e4587bb35153a3cf8780f92aab8d6272451885c5a901da090f345cef' 
  AND token = '+uTGdvlZunseV8OwNRDw79dZdHA/DILX5njHeBLMdto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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