SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ddce72473c31f21f0eb930674baa11aa966f9e9d3a31e470ab8f46db5b1635b' 
  AND token = 'uVZK/RQOuPmiY8iyUZRStbFkhyEqyDQxWWg+iuwPS3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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