SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36d65c510d43ba3347ff135632bceae8348594d1c722ac617694f69b5b66d5eb' 
  AND token = 'FyxxozW43Zmv+3KdTVsB+t3fUnJLH55meVhDLa72kXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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