SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7235a9782eb1d3b5b5719cf86d2236fe09146b2fccfc94e17b85d8ac4bd591b' 
  AND token = '8iGPfj/qRcZLakhyMPQNqZmpWjsB7PoJVC5ZU+5OXUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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