SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f58023c349b186acc932de06743bd1a0c8105b1143dbc6826b15bbb7e9de8a9d' 
  AND token = '0AeIe2XFy4+Boy+VXwS/QdwlpKRa3rFHxB5u688gmoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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