SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3a8d411175014e27faf8560877bc284b0745d4c1aa433942fd7836bfdba85cf' 
  AND token = 'WIfhRDZCYy4a5YvBSvFWVjNR4PvjyRVGOhvsfYIMpdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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