SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd46af470d794f811b3bfde7d8bbb6ff1de78413baf49bf31400826a1902d16a6' 
  AND token = 'WjjALY3thQDoPJTAypIYOYd6gZpmVmNEJpq/W9+ewts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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