SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b966e09926ebe684976144c2a2ce21317930164b8175ebedd973ef7dcbd0abcf' 
  AND token = '08jfGvVTbeXe+MtD5DsnFNotaLMrKtZrtIOpcC6bOgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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