SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5567eef931805f1ae567dc61cc6bf5c4cb666333ba9f189a2c6dab2791dcdf87' 
  AND token = 'tCrkNKzEJDZL0+bllV3mMkDTeu3gHvnMiUa8v7K7tpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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