SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b653f27eb3e916441ad617806bbb93d199045cce3b6304d98aa48c8932da2f2' 
  AND token = 'Khp0VHRn0OQ7ta3kr0fEg2OXl8SPTdWSG+aZs4nsUAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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