SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38e96b6c06ac2881d86235b7ee9fd079ac8df085cbf743f4808913f8fd9d7a21' 
  AND token = '3MPu5c72Cp7mwLP5UcH6T4qsT3r1cC/Mi4tMIWc4pCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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