SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ff7e9a368e4aba27b7405ede447fb1eeaf9d1fd4225e04ab7cfd48be8ae25fd' 
  AND token = 'f11nM7g5CJzZBGiJ2veyobCVfJotCTBXkV3kO6Zpr/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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