SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be6c25bd3a6009bcb9dadccd29212d47fd362eb9608b9d2e3e5dbba432a32e4f' 
  AND token = 'C5thHrBVKP6ue9JThqYXJ5xkrlYS3VA1Fc2y+ToAppw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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