SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb01084899e9cea30be7b41ffcf515f1ddb990682fdfb044a057cffa68c62834' 
  AND token = 'hujBct+fgst4TJuonKo2feiVz0Fb8t/mqm6gGC7uPC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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