SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e2e9539a19e3112dec5c9aa7b09e755831083dcfad967a3201fd7505f2f0f02' 
  AND token = 'thYxvv5/N5l17QOQTlbyQ75I5ZPZAGFM3VM1gteVPBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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