SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '077c9c443ddacaab5e83fcf223a0df2433b64da010d5848f026f46e1c5674c1c' 
  AND token = '/nj+SdQJs2KMU7M3ZBdhRlozbzk547wNGZlgsO4JlJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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