SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1594720f1c79cf0eccc1da013dacf7ff72645259529ec799521df5318d320c23' 
  AND token = '9bheresNf83us2BQN8jCrNyrawOqOcGohIUzFsTowys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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