SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ed235c7db1ba240ac43debd9cfc8c3d0aba0291255efdd582e86962d7ff9682' 
  AND token = 'g58AbPs+8se/FoNZU0VIG850SVlHhxMRRgsYfQ2HgUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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