SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5cce92c86c5981d8ba1c566ee69fc1ee42c9a5550197262305c4f1834733f6f' 
  AND token = 'kXxkpnm1avZQ1raq1IJiS5LNohPZESYXIhYIz9eC9r8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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