SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7821db37a02c614e88fe482dc81ba7f2af4170b973e149bc1f7617749f175dad' 
  AND token = 'frXzxKhwQMl4XLM5PpPljehaPlykmwvtY1LNuXtLdPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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