SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd556006e5e6426cd035b45dd4df88f7fe1ddd7925aa8ef4efe7a8ea0792f696a' 
  AND token = 'oKIjf3OjBBUm0Z+XoO8+vhu8BDH2LmPDxwAU23OWQAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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