SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33a49cca5e3e490cae075321979dbe330915159c34ff5573521d740ae0dbac68' 
  AND token = 'KDmgABP8GBXlhKk7Mv+AGHoH9owBibuafwJPfYxZEuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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