SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f5f579838183d4fcde860237e3deaefad0487af383698f80d2e9505281fa021' 
  AND token = 'VvhTI2KlX8DYuXUvyk3jVWdo/2DZJaIKho3QSujtw14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}