SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8407cc09e89509715e6fa4b702033578c67112fedd0dd93bf6e7099fb486c4bc' 
  AND token = 'mXeIiETV/qQ+o2Vozf9SUKBwy+DtmVOSyYU0hUx5IhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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