SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7581402e68ffa07150f19ea13dff64f0bc048641ac67fbd1cd76ac0e98d5f19' 
  AND token = 'ny7zkTbPA3BVjOhRpjC8VK+xiXqpP9LH1wGZcgqU20Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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