SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe0bd78bef309f7da6ae86474444149f6546a4d6dea00592881176cd963931e7' 
  AND token = 'yvlQdqCnbV4UEClEmKhxRIkmjjXbG2NSp/uW6IYJslA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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