SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '095f1f26152b7eb45327597e4de06f5d673e884bf89383c8a1d7e5147ba7fbc4' 
  AND token = '9pRKhpI1REKDG8OyvHRhF9lJEbTtA6K1BUliMDrWmZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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