SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c3b103516b932fbcbcf9fcd3fe192120283a8bceec3ad4f563a1126fcf67f5b' 
  AND token = '4igVNJ8kXdf42XKyn+95VkX0YjqWVc9P4sevyEfF1lI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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