SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '587028c1141aa453bceaf6c1f544d4debaca0adfa19e2043d72ede9a37b41c61' 
  AND token = 'Snty3TvhtmjK7Xdca40WF+0ffmB3sP4qMPmeRjvxVPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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