SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '741ebea1e3742a9b30ed040d79ed12309ba1fc5ede45968b7a3b92d96e02b02e' 
  AND token = '2wK8wGAApOplFbxN4WdTmIGEbgPEQdRkYbMbc6LaSqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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