SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f697ace8396856f3a545976547f7d395457ca7f6d5439eb4261c3aa08e613a5b' 
  AND token = 'oA5bxXbvJSsq0HmKwbv2MY92Bnmzune6Z18WpNgCVLM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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