SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83be40fa104176ed436d041ad50352acc6b5f3d8ac45994c4e36f46288a44741' 
  AND token = 'XoEmZlZSQVseTp/GLN8KxicoTgveuWLZ50KWpqi4zGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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