SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90f4c8f44c0349a8ffffd954fae97fbb98998b0a21ad51417f14b2af1137d24a' 
  AND token = 'aInwMkGkBQfeEZrhrmNeM/WIQbUmyFDwc7gZbW/3vhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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