SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d7182d440a62e44a65e59d6d475b44f28a1f0d8f2764f1999af4d4c3f474bba' 
  AND token = 'EnGtBOavfG+1zZ8p0VqS/KCuK3/wSlPqUdi9xZOe4gw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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