SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e316b100ce97e30818e7dfcac9324d39bd2484618b0722a4953def6430af04f8' 
  AND token = 'rGu1Lg85dmOQnlDNwb5wHd/XbDeSYl1P2QHLpQXs9WI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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