SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b109103c0ce891fcc725ef732c651d3ff70e831375edec8ea0f59ace791c86e' 
  AND token = 'BGPWYdyvewP2RzYVdKpcbPqEZLdHLaor5QFrnEw7FSE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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