SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '083ffb6caf020c32a1e7dcff8050350dfe58d4e4fa07cdbabfcae18a8f3475ba' 
  AND token = 'zG7W3wl79drpRs9s4W75I3UqF0SXo2YGAVnKQNMOMsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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