SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b80ef0176c922455448463e9831bb49595e5f0914e9ab3a7adff06ecac2b251' 
  AND token = 'Nu+DdyAIp94WgM8iyte3lC9ePHflR5UPBsDpqDfYZBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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