SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd8fd15f496517dda663419c1b8b93bb8118794777bec56f3f9b9c19936d3274' 
  AND token = 'Jng6DQNa9N7a8lWxUGy/wghm2/Eh+Cr0C/w5cR/zJvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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