SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bfe75b43fc42951db3cc2a9652db145cd67740331664eb44f7adae3aa8676fa' 
  AND token = '2VC4TOgUCi4km7J34+3HlDMl1uJjjwvuZsGl2SZ1xX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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