SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37f8f5edb98169f3bf43687bbd0c9181b2dd6d9f9d742f61c346323389080438' 
  AND token = 'KJO8BIuzxPFok+seqgExpqiz05PdnuklECRoITKWYzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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