SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fc00a2be36b040e35503440a251a815856aa8a7efa6ec201422a2e404b66044' 
  AND token = '179iirHjKbsgNsVHCy5rsDuSEHMV/wFKjIHMMBvceDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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