SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20a3e85747102ebd44218457543307747da30a5d5cc9aaf3f4face3c86adba00' 
  AND token = 'gdFORnBYtx9ginFJRx6Fw3n8uc5HHSE81tvefCc8V+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}