SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2cadb4718b0568368dcbc393819e8e7cc15a488307a4bbf3e091a085d50006f5' 
  AND token = 'RKGtSpjBLUt3wWl22uzuIOCI/K/IPD8XJitfhDRdKB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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