SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb26f575c484faa841c0fa3711aac7a6ed59be9079c7f779e334fbd4402a8708' 
  AND token = 'rDDcpZFNTv9yZr4/aUnhrzc5IEtBIG+34EzfQ6pLwZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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