SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '862e13b1e4cb02e94846fd33faffdf8e797154a117f644958ebbc6db9cf91498' 
  AND token = 'tLZyAGwnq9c9JZnAIh4x02wIZtuU4k5JgEqNgNRvY0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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