SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '712a3e8e342668299dc39935cee3422aea83a6734aa3db1d8957428e5fae218a' 
  AND token = 'Nx3t1IY06kgp8Acfl90+6mmEgBWSsjdDiWAuCZayHHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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