SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4adcce1cdcc362cac6a40fbb9c3d45d2ed9f3716895d2342103cf29cb22902ea' 
  AND token = 'hAxn+dieLsbrCAgOeW4AQ+ne6Ld2e+64DoGKQHkmq/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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