SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f1f32bf467d4ea5370a281ff4583710c1c3817945faa5794f16c6a995167197' 
  AND token = 'PtssgS+SyKtM39lKp32BkV0P/6zkm8qon2EAmZpfsPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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