SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26aef891d0859a370499c1361d216fb23bd5f18afef1cefdb99555ff07ea1fc5' 
  AND token = 'tCqmV+htsYN98nlOrhjW/uyCsbDYxFOubgJ8VGVDXhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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