SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be63ef4c55dc31395d9c5ad97eac21780927568fbdc2f8a078816054f39c5206' 
  AND token = 'iIw7kLzLqoWphxFqJGvKIPWkAYDNgnQG5/Ui+wJYTWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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