SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8aa4a8a1fa43a5827e09713756e774188896b7e18142ed032c04279dbf9e1be' 
  AND token = 'F40hqhBGbh79nkHF8VNgnmT1y8EKfMaLZVPorIrwhYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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