SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aab50eb218ec9d375c74c561f3e4f0507ff5064fb168c20523a10854ccab9085' 
  AND token = '3/X62gHPibO9v+OUgYxPVm2BlhgJVTYVQTH0bd9Tz/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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