SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36113dbf69c78e2e69967c7b3ee66427034246907f294cc58232fbd3bc0e91d5' 
  AND token = 'CfFRGal9kCWrwI+7KpbyzxNqAKnL5U8JuVoxX3VjTlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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