SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49f2f052f5a06641634be2063f37080f09648012b7ce59856734fe0b81b0c0a5' 
  AND token = 'ZghwKVUrr+/SgQ7nJEBv3u8TwnkKNHbv4JJcJ1rwAho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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