SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ca4f26c99022c5953e891a9b76a4c555b91b74295765f3d8fcfc5bfd8f7214d' 
  AND token = 'jMYAQZ1RZjg7IbpTT/AEKudtBXIz7n+LTLgz9wSoXQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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