SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '834bd3e6251d4992ccaf62cf9797af5c1c02f002b1b3de1456ef9c91ebf1139a' 
  AND token = '60kkkxkCwScvb1zp0ZcQfQ4Tgic3otYT87H8blockeg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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