SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '78d1fac64ea4725382fb5cf4932435ca7b57d6e7ad2e168514dec606c770f8d8' 
  AND token = 'duWHzgZfjIgutMgabkfbPNfP/1ERzBlY7oMGT7JDBvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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